Reading · The Pharmacist · RSS Amplifier

Turning 40 is a strange birthday.

You’re not old.

You may not even feel particularly different from 35.

But suddenly the things you used to get away with start becoming harder to ignore.

The extra weight around your waist doesn’t disappear as easily.

You miss a few nights of good sleep and feel it bigtime.

Recovery somehow feels slower.

Your blood pressure, cholesterol and blood sugar start appearing more prominently in conversations with your doctor. (and your age group)

And then there’s testosterone.

If you’ve spent five minutes on social media, you’ve probably been told that it is disappearing, your metabolism is collapsing and the solution comes in a vial, supplement or expensive “optimization” program.

There’s just one problem.

Human biology doesn’t work like that.

There isn’t a switch inside the male body that flips at 40.

But there are biological processes that become increasingly important as we move through midlife.

Let’s kill this one first.

Your metabolism does not fall off a cliff when you turn 40.

One of the most important studies on human metabolism examined energy expenditure across people ranging from infancy to 95 years old.

After accounting for body size and composition, researchers found something surprising:

Energy expenditure was relatively stable from roughly age 20 to 60.

The more obvious decline appeared later. [1]

So why does your belt sometimes tell a different story?

Because metabolism isn’t the whole story.

How much you move can change.

How much muscle you carry can change.

Your diet can change.

Your job may become more sedentary.

You may sleep less.

You may drink more.

You may spend eight hours at a desk instead of moving around all day.

And gradually, the equation shifts.

The lesson:

Don’t blame an imaginary metabolic cliff.

Look at what has actually changed

At 25, muscle is often about looking good without a shirt.

Later in life, it becomes something much more important.

Physical reserve.

Age-related loss of muscle function eventually contributes to sarcopenia (a progressive skeletal-muscle condition associated with falls, fractures, disability and other adverse outcomes.)

But here’s the part men need to hear:

Loss of muscle is not synonymous with inevitable helplessness.

Resistance exercise remains effective as we age.

Research reviewed in BMJ publications shows that resistance training can improve muscle strength, mass and physical function in older adults. [2]

And protein matters too.

A large meta-analysis published in the British Journal of Sports Medicine found that adding dietary protein during prolonged resistance training produced additional gains in muscle mass and strength in healthy adults. Benefits did not continue increasing indefinitely as protein intake climbed; in that analysis, intakes above approximately 1.6 g/kg/day did not produce further resistance-training-related gains in fat-free mass. [3]

That does not mean every man needs 1.6 g/kg.

It means protein matters but more isn’t automatically better.

The bigger message is simpler:

Don’t wait until old age to start protecting muscle.

Build it while you can.

Keep using it.

A man can weigh roughly the same at 45 as he did at 30 and still have a different body composition.

That’s important because fat isn’t simply stored energy.

Where you carry it matters.

Excess abdominal and visceral adiposity is associated with cardiometabolic risk.

And this is where midlife habits begin accumulating interest (whether they’re good or bad….)

Less movement.

More calories than you need.

Poor sleep.

Alcohol.

Loss of muscle.

Years of these small differences can become a very different body by 50.

So instead of obsessing exclusively over the number on the scale, pay attention to the bigger picture:

your waist,

your strength,

your activity,

your blood pressure,

your lipids,

your blood glucose,

and the direction they’re moving.

Midlife health is less about one number than the trajectory of several.

Now we get to the bit were people would rather not say anything about it…

Testosterone.

Yes, testosterone levels can decline with age.

No, turning 40 does not automatically mean you have “Low T.”

And feeling tired does not diagnose testosterone deficiency.

The Endocrine Society recommends diagnosing hypogonadism only when a man has relevant symptoms or signs and consistently, unequivocally low testosterone concentrations, confirmed with appropriate testing. [4]

That distinction matters.

Because fatigue, reduced libido and low mood can have many causes.

In a July 2026 statement, the Endocrine Society specifically highlighted potentially reversible contributors such as obesity and certain medications and reiterated the importance of proper testing before testosterone replacement therapy. [5]

Their guidance does not support prescribing testosterone simply because a man is getting older.

So if somebody tells you:

“You’re 45. Of course your testosterone is low. You need TRT.”

That’s marketing.

Not a diagnosis.

Testosterone is a hormone, not a personality score.

Treat genuine deficiency seriously.

But don’t turn normal aging into a disease just because somebody can sell you the cure.

Men tend to think of erectile function as being about one thing:

sex.

Medicine sees a bigger picture.

An erection depends partly on healthy blood flow, which means erectile difficulties can have vascular and metabolic causes as well as hormonal, neurological, medication-related and psychological ones.

That doesn’t mean every episode of erectile difficulty predicts heart disease.

Far from it.

But persistent erectile dysfunction deserves a proper medical conversation rather than embarrassment—or an automatic assumption that testosterone is the answer.

Your sexual health isn’t separate from the rest of your body.

It is part of it.

Blood vessels don’t know whether they’re supplying your heart, your brain or your penis.

Looking after vascular health matters everywhere.

Get 50% off for 1 year

Your cardiovascular system doesn’t suddenly discover aging at 40.

It’s been keeping score for decades.

Blood pressure matters.

Cholesterol matters.

Smoking matters.

Diabetes matters.

Physical activity matters.

Body composition matters.

Family history matters.

The mistake is waiting until something goes wrong before caring about any of them.

Think of cardiovascular risk as exposure over time.

One elevated reading isn’t your destiny.

But years of untreated risk can matter.

This is one reason midlife is such an important window.

You’re not trying to become immortal.

You’re trying to change the direction of the curve while there’s still plenty of curve left.

A lot of men treat cardio as punishment for eating.

That’s a terrible way to think about it.

Aerobic activity trains your cardiovascular and respiratory systems and is associated with major health benefits.

Current World Health Organization guidance recommends adults accumulate 150–300 minutes of moderate-intensity aerobic activity per week, or 75–150 minutes of vigorous activity, or an equivalent combination.

WHO also recommends muscle-strengthening activities involving the major muscle groups on at least two days each week. [6]

Notice something?

It’s not:

cardio or weights.

It’s:

cardio + strength.

You need an engine.

And you need a chassis.

This may be one of the biggest traps of middle age.

You’re tired.

You assume you’re getting older.

So you accept it.

But fatigue has many possible causes.

Poor sleep.

Stress.

Depression.

Medication effects.

Alcohol.

Sleep disorders.

Medical conditions.

And one problem worth knowing about is obstructive sleep apnea.

If you’re regularly snoring heavily, waking unrefreshed, struggling with daytime sleepiness or somebody tells you that you stop breathing during sleep, don’t simply label it “getting older.”

Talk to a clinician.

Because “I’m tired because I’m 45” isn’t a diagnosis.

This one is easy to miss because stress doesn’t always look dramatic.

Sometimes it looks like success.

A mortgage.

Children.

A senior job.

A business.

A divorce.

A parent who needs care.

Money problems.

A phone that never stops.

Emails at 10 p.m.

And the feeling that you’re responsible for everyone except yourself.

Short-term stress is normal.

Your stress response exists for a reason.

When your brain perceives a threat, it activates systems involving hormones including adrenaline and cortisol. Heart rate rises. Breathing changes. Energy becomes rapidly available.

Useful when you’re dealing with an immediate threat.

Less useful when the “threat” is your inbox every day for five years.

Harvard Health describes chronic stress as repeated activation of this response and notes evidence linking it with high blood pressure and psychological problems including anxiety and depression. Chronic stress can also disturb sleep and influence behaviors that affect health. [7,8]

And that’s the point many men miss.

Stress doesn’t stay inside your head.

It can influence how you sleep.

How you eat.

Whether you train.

How much you drink.

How patient you are with your partner.

Whether you can switch off.

Whether you’re mentally present with your children.

And how you feel when you wake up tomorrow morning.

The dangerous version isn’t necessarily the spectacular breakdown.

Sometimes it’s the man who says:

“I’m fine.”

And keeps saying it for ten years.

Managing stress doesn’t mean eliminating every difficult thing from your life.

That’s impossible.

It means developing ways of preventing constant psychological pressure from dominating your physiology and behavior.

Exercise can help.

Sleep matters.

Social connection matters.

Relaxation techniques can help some people.

And sometimes the right intervention is speaking with a mental-health professional rather than trying to outwork the problem.

I’ve become particularly interested in this subject because my first work experience in the clinical setting was in a mental health hospital pharmacy. So I wrote a book about stress management. ‘The stress management handbook is a practical, science-backed guide designed to help you reduce stress.’ It discusses stress management from a practical perspective and provides techniques and tips to mitigate stress.

Here’s the link to get your copy!

The central idea is worth remembering:

You can’t remove every source of pressure from your life.

But you can change how you respond to it.

Another bad story we tell ourselves:

“I’m getting old. My brain isn’t what it used to be.”

Aging does affect aspects of cognition, but midlife forgetfulness isn’t automatically evidence of neurodegenerative disease.

And brain health isn’t isolated from physical health.

Sleep matters.

Exercise matters.

Cardiovascular risk matters.

Mental health matters.

Alcohol matters.

Social engagement matters.

This creates an important shift in thinking.

Looking after your heart and body is also part of looking after your brain.

The same walk isn’t just “cardio.”

The same night’s sleep isn’t just “recovery.”

The same workout isn’t just about your biceps.

Health systems overlap.

Osteoporosis is often framed as a women’s health issue.

Men get osteoporosis too.

And muscle and bone health are closely connected to maintaining function and independence as we age.

Resistance exercise is therefore doing more than making you stronger.

You’re building physical capacity for later life.

Think about the things you want to be able to do at 70.

Carry luggage.

Climb stairs.

Get off the floor.

Travel.

Play with grandchildren.

Walk up a hill without thinking about it.

The preparation for that life doesn’t begin at 69.

It begins decades earlier.

Here’s what nobody warns men about.

Turning 40 isn’t the event.

What happens between 40 and 60 is.

You can spend those decades slowly moving less, sleeping badly, accumulating abdominal fat, losing strength, ignoring blood pressure and treating stress as an unavoidable part of being a successful adult.

Or you can start paying attention.

Not obsessing.

Not biohacking every molecule in your bloodstream.

Not buying 14 supplements.

Paying attention.

Lift weights.

Use your cardiovascular system.

Eat mostly nutritious food.

Get enough protein.

Don’t smoke.

Be sensible with alcohol.

Protect your sleep.